<template>
  <div class="home">
    <img class="home_img" src="@/assets/bg.png" alt="">
    <div class="home_btn_w">
      <div class="home_btn" @click="goToSelect">
        <div class="dot">开启</div>
        <div class="pulse"></div>
        <div class="pulse1"></div>
      </div>
    </div>
    
    <div class="home_info">
      <p>版权归北京市气象服务中心（@气象北京）所有，</p>
      <p>转载请务必注明来源。</p>
    </div>
  </div>
</template>

<script>

export default {
  name: 'Home',
  components: {

  },
  methods: {
    goToSelect() {
      this.$router.push('/info')
    }
  }
}
</script>
<style>

.home {
  width: 100%;
  height: 100vh;
  background: url('../assets/bgall.png') no-repeat center;
  background-size: cover;
  position: relative;
}
.home_img {
  width: 100%;
  height: 120vw;
}
.home_info {
  text-align: center;
  font-size: 12px;
  line-height: 1.5;
  position: fixed;
  left: 0;
  right: 0;
  bottom: 20px;
  color: #fff;
}
.home_btn_w {
  position: absolute;
  top: 120vw;
  width: 68px;
  height: 68px;
  line-height: 68px;
  left: -6px;
  right: 0;
  margin: auto;
  border-radius: 50%;
}
.home_btn {
  width: 68px;
  height: 68px;
  position: relative;
  background: #ea9a9e;
  font-size: 26px;
  color: #fff;
  text-align: center;
  border-radius: 50%;
}
/* 保持大小不变的小圆点 */
.dot {
  position: absolute;
  width: 68px;
  height: 68px;
  left: 0px;
  top: 0px;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  border-radius: 50%; 
  background: #FFFFFF;
  color: #25A188;
  z-index: 2;
}

@keyframes warn {
  0% {
    transform: scale(1.1);
    opacity: 0.6;
  }
  25% {
    transform: scale(1.2);
    opacity: 0.7;
  }
  50% {
    transform: scale(1.3);
    opacity: 0.8;
  }
  75% {
    transform: scale(1.4);
    opacity: 0.9;
  }
  100% {
    transform: scale(1.5);
    opacity: 0.0;
  }
}
@keyframes warn1 {
  0% {
    transform: scale(1);
    opacity: 0.6;
  }
  25% {
    transform: scale(1.1);
    opacity: 0.7;
  }
  50% {
    transform: scale(1.2);
    opacity: 0.8;
  }
  75% {
    transform: scale(1.3);
    opacity: 0.9;
  }
  100% {
    transform: scale(1.4);
    opacity: 0.0;
  }
}
/* 产生动画（向外扩散变大）的圆圈 第一个圆 */
.pulse {
  position: absolute;
  width: 68px;
  height: 68px;
  left: 0px;
  top: 0px;
  border: 1px solid #fff;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  border-radius: 50%;
  z-index: 1;
  opacity: 0;
  -webkit-animation: warn 2s ease-out;
  -moz-animation: warn 2s ease-out;
  animation: warn 2s ease-out;
  -webkit-animation-iteration-count: infinite;
  -moz-animation-iteration-count: infinite;
  animation-iteration-count: infinite;
  box-shadow: 1px 1px 30px #fff; /* 阴影效果 */
}
/* 产生动画（向外扩散变大）的圆圈 第二个圆 */
.pulse1 {
  position: absolute;
  width: 64px;
  height: 64px;
  left: 0px;
  top: 0px;
  border: 2px solid #fff;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  border-radius: 50%;
  z-index: 1;
  opacity: 0;
  -webkit-animation: warn1 2s ease-out;
  -moz-animation: warn1 2s ease-out;
  animation: warn1 2s ease-out;
  -webkit-animation-iteration-count: infinite;
  -moz-animation-iteration-count: infinite;
  animation-iteration-count: infinite;
  box-shadow: 2px 2px 30px #fff; /* 阴影效果 */
}
</style>

